Comparative Study of ZF, LMS and RLS Adaptive Equalization for alpha-mu Fading Channels

Abstract

Wireless communication systems generally endure severe fading and interference caused by the time-dispersive channel. Major transmission distortion is produced by channel multipath propagation and overlap of subsequent symbols. To counteract channel response, equalization techniques are employed to operate on channel output and recover transmitted signal at the receiver. This work investigates equalization of channels undergoing alpha-mu fading distribution, which models multipath propagation in millimeter Wave (mmWave) and sub-Terahertz (sub-THz) frequencies bands. Three equalization algorithms, which are non-adaptive Zero-Forcing (ZF), adaptive Least-Mean-Square (LMS) and adaptive Recursive-Least-Square (RLS) are implemented and addressed in terms of Bit Error Rate (BER), Convergence speed and implementation complexity. Monte Carlo simulations are then carried out to compare algorithms and assess performance by varying multiple parameters such as training lengths, channel order, equalization taps and diverse fading conditions.